Interactions of the human being with his/her environment (such as friction through movements) causes an accumulation of a static charge on the human being. Humans typically wear non-conductive clothing (e.g., rubber-sole shoes which are an efficient insulator), which enhances the accumulation of a static charge by the human. More specifically, clothing is often the interface between the human and the ground. When the interface has insulating properties (e.g., shoes with rubber soles), the human accumulates a static charge. As such, when an object representing a ground is contacted, the human feels an unpleasant static shock as the charge is discharged to the ground.
In some workplaces, the level of static charge on workers is controlled. As an example, in the field of electronics, a 100 V charge may cause damage to electronic components, such as the erasure of data on magnetic data medium, even though the worker does not feel the discharge of such a charge. In operating with hydrocarbons (petroleum and gas industries), a 50 V charge may spark flammable vapors. In the plastics industry, static charges may be of such magnitudes that severe injuries resulting from electrical shocks have occurred. The control of static charge is therefore important, whether it be for the security of workers or for maintaining levels of productivity.
Protective equipment, such as shoes, wrist bands, heel pads, ankle bracelets, has been developed to control the charge of workers. However, if such protective equipment is highly conductive, there is an increased risk of electrocution for the wearer. The wearer of highly conductive protective gear may become a ground for high-voltage machinery or wires.
A plurality of products have been developed and patents have been granted to address the need for conductive, insulated or antistatic gear. Examples of patents include U.S. Pat. No. 493,782, U.S. Pat. No. 2,261,072, U.S. Pat. No. 2,712,099, amongst others.